For the camomile cake
- 3 tbsp camomile tea (preferably whole flowers)
- 120g/4½ oz unsalted butter
- 8 free-range eggs
- 250g/9oz caster sugar
- 250g/9oz plain flour
For the buttercream
- 420g/15oz baking margarine
- 850g/1lb 14oz icing sugar
- ½ tsp elderflower cordial
- 2 drops elderflower extract (available online), optional
- yellow food colouring gel
Preheat the oven to 180C/160C Fan/Gas 4. Grease and flour a 20cm/8in springform cake tin.
For the cake, crush the tea in a spice grinder or pestle and mortar until it is a fine powder. Melt the butter in a saucepan and stir in the tea. When melted, remove from the heat.
Crack the eggs into a large mixing bowl and beat in the sugar using an electric mixer. Beat until the mixture is thick enough to hold its shape for several seconds when drizzled on its surface (known as the ribbon stage, this can take around 15 minutes). Sift in a third of the flour and fold in using a large metal spoon. Sift in another third of the flour and fold in as before. Sift in the remaining flour into the butter mixture and mix well then gently fold into the rest of the batter.
Transfer the batter to the tin and bake for 45 minutes (checking regularly to make sure it doesn’t over brown). When cooked, remove from the oven and leave to cool in the tin for 5 minutes. Remove from the tin and leave to cool on a wire rack.
For the buttercream, using an electric mixer beat the margarine, icing sugar and elderflower flavourings together in a large bowl. Keep beating until white and fluffy, then set aside in the fridge until needed.
To assemble, if necessary, trim the top of the cake to ensure it is flat. Cut the cake in half horizontally. Add a generous layer of buttercream to the bottom layer of cake and then place the other layer on top. Transfer the cake to a serving board or cake stand.
Spread a thin layer of buttercream all over the cake (also known as a crumb coat).
Fit a large piping bag with a medium closed star nozzle. Smear streaks of the yellow food colouring on the inside of the piping bag using a pastry brush or a round tipped knife.
Fill the piping bag with buttercream and pipe a few test dots until the buttercream comes out two-tone. Starting at the base of the cake, pipe lines of dots all around the cake to cover the sides, then start piping the top in circles of dots starting at the edge and working inwards. Place in the fridge between icing levels if you find the buttercream is melting.